Toaster Oven Reflow Soldering (BGA)

Doing solder reflow work can be expensive and difficult, but thankfully there exists a simple and elegant solution: Toaster Ovens. This project shows my preferred setup and the tricks that make the process run smooth. In this example I'll focus on doing reflow of a BGA (ball grid array).

Step 1 Find a toaster oven.

You're looking for two main things, an adjustable temperature knob, and a timer that will time down. The more precision you can get in the timer the better.

Also, if you can get it, some sort of forced air flow will improve the uniformity of the oven temperature, but you have to make sure that the air flow isn't powerful enough to move your components around.

Comments

[pyper]

When doing SMD stuff at work I tend to use "tacky" flux which comes as a gel. It not only serves as a flux but makes positioning IC's a lot easier as you can sit them on top of a little blob of it and then fine tune their position with your tweezers (aligning TSSOP48's would be pretty much impossible without it IMHO) It also helps stop things getting blown about in the oven too!

[hellstudios]

hey, although this worked with my laptop's video card awhile ago, i just tried it with a desktop motherboard at the temperatures you specified and it melted the plastic and caused one of the capacitors to explode... ruining a perfectly good motherboard that just needed a simple fix. :(

I looked further into reflow and other resources say that the temperature should be between 390F to 420F. NOT 450F. please edit your instructable so other people don't make the same mistake i did.

also, try not the breathe the smoke in that is released from the motherboard, I accidentally did and now I feel light headed.

[zack247]

some people have used butane jet lighter style torches to reflow components with high levels of success, i tried and had i not accidentally pulled off some pads (because i didnt wait) the palm pilot would have worked fine again.

people have used these torches for laptops more specifically, since most people arent smart enough to try it ont eh desktops, since they figure motherboards are eas to replace anyways.

[scottinnh]

Valuable life lesson here if you can forgive yourself for damaging your board. Always seek out more than 1 source of information.

The author's example is building a BARE PCB up with no mention of plastic.
The author could not anticipate that someone would try to reflow plastic parts, or inhale the fumes. You can not document common sense in the space of a tutorial.

Since you wanted to reflow a populated board, I would have sought one of those tutorials out (there's lots of them, particularly for the x-box, as reflowing the board is something many customers have needed to do).

By the way, your motherboard was not ruined. Capacitor replacement is one of the easier repairs to make. $3 on ebay would get you a replacement cap of the right size, and you could solder it back in with a cheap iron.

I'll also throw in, if you want to do localized reflow without heating the whole board, a heatshrink gun can work (Sparkfun has a Heaterizer 2000 for like $10). You can still make mistakes of course...

If the part is valuable and you are a novice, best to watch someone else do it the first time (youtube is good for this!)

[hellstudios]

Indeed.

it was a crappy little socket 478 mobo anyway, Yes, lesson learned, atleast i didn't do it to a more expensive component.

[Spuzzum]

A cheap screw up then. :D

Reflowing "smt" chips, resistors, caps, or any other "surface mount" components on a motherboard is the FIRST process they do to it.. BEFORE adding the other components that are "heat sensitive".. ie: "melt at high heat". The plastic based components are added later.. by hand.

Think of it this way.. would you allow your motherboard to run at 390F - 450F? No. Reason is, those plastic components will fry.

There's nothing wrong with this method. Many use their bigger ovens as well. You just need to be sure you are familiar with electronics before you attempt to do something like this.

If you need something directed at a single component on the board, then look for the instructables called "DIY Hot Air Soldering Iron". A "reflow pen" is what you need. More control of where the heat is applied. ;)



Chhers.......................

[solder_bug]

Lead-free solder has a higher melting temperature. 420F/215C is peak temperature for lead bearing solder which is ban after year 2002, Lead-free solder has peak temperature of 450F/232C for 1 min or 425F/217C for 3 min..... Never reflow PID's and plastic parts in IR oven together with SMD's without covering them with kapton tape.

[hellstudios]

By IR you mean infrared? I was using a normal kitchen oven with the mobo suspended on tinfoil cubes.

[evanwehrer]

Check this out: http://www.sparkfun.com/commerce/product_info.php?products_id=81
Toaster oven Reflow Controller
I have nothing to do with sparkfun but I think its a really cool kit.

[hintss]

and...you program it yourself. and sparkfun's toaster oven works better than their reflow oven :P

[5150tech]

Nice job. I have done thousands of BGA profiles professionally and I like how this boils it down to the basics time and temp.  the only thing I would do is rewire the oven so both elements run together so you soak through the component. I think that will get everything up to 183c (for lead solder and 205-230c lead free solder) pretty quick. on the other hand, if it's not broke don't fix it.

[vxir]

How do you make sure that all the balls are connected?  Won't the body of the chip block any inspection?

[lilimike]

What about the solder?
Did you add solder to the pads?
Will any kind of solder do the job?

[Macka]

I believe the balls on the chip are balls of solder that are preplaced, so no further solder is necessary.

[CCronaldo]

Do you know where to buy solder paste and how to apply it if it is not a reflow, but a first time application? I like your instructable, it is well done.
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quang cao online | quang cao

[Earths_hope]

Wow! It's amazing what you can find in what would be useless little electronics!

[beneaton]

For an even simpler approach take a look at http://www.reconnsworld.com/griddle_reflow.html.

[killersquirel11]

(removed by author or community request)

[toomanyplugs]

I thought so, too. Just remove the last period after you click the link and try again. The period got captured by the link formatter.

[bucklipe]

What about an external motor with the fan shaft going through the bottom(?) with a speed regulator. This way the fan blades could be aluminum and large enough to move the air slowly. With the motor mounted outside the limiting factor would be the melting point of aluminum, not a factor with the temps used for solder.

[ZBM]

question : for a forced airflow would two holes cut in one at say the top left and at the bottom right with a PC fan attached at one of the holes work?

[dUc0N]

I can understand where you're going with that, but it'd probably hurt more than help, as the fan would be pulling cooler air from the room into the oven, and then forcing nice hot air out the top. A better solution (if you want to mod it yourself) would be to come up with a fan that can withstand the temps you intend to use the oven at (plus a good safety margin, an additional 10-20% or so), installed on the inside of the oven. The best positioning would probably be right at the top, aimed down, where it'd suck the hottest air from the top and channel it directly onto the part you're working with.

[sparr]

I want to stress that the airflow should be *VERY* slow. You are not trying to bring more air in contact with the part (which is what small fans normally do, like on heat sinks). You are just trying to even out the temperature of the air, like a ceiling fan.

Imagine a computer case fan spinning at 100RPM instead of 2000RPM. Except a computer case fan would melt in a toaster oven, but you get the idea.

[ZBM]

thanks for the input

[colin]

Actually, you probably want to avoid blasting the air straight onto your board. There's nothing worse than having components slide around when the solder is molten. That being said, a gentle breeze should be fine.

[dUc0N]

Point taken, especially considering the fact that you're the experienced one. =-)

[cjeung]

I've got a video card with a faulty connection in it's bga connection. Using this fine instructable, I have a question. Will I have to completely remove the chip, to rework solder, or can I just toast board and hopefully the faulty connect will reflow? In other words, do I have to remove chip because I'll need to apply flux?

[sparr]

If you try to toast the board, there's a chance you will damage other components that were added after the original soldering step. I would not advise it, but if you are determined to try then remove everything that can be removed (esp plastic parts and stickers and sticker-residue!) beforehand.

[cjeung]

Zounds! This was an excellent tip. Saved myself beucoup dinero on a laptop repair. Thanks aplenty!

[inventorjack]

I just received a bunch of FPGAs with BGA type package, so this'll come in handy. Thanks for the info!

[arash.crouse]

Such a cool idea.

[alex-sharetskiy]

what were you using the Gyrometer for?

[drsoubhi]

Dear Mr. Colin

Hi,

I have an old Minolta Dimage 7 Digital Camera.

I think that the BGA Processor has some cold welding.
Is it possible to use your procedure to reflow the affected AGP pins?

Also you didn't mention the duration needed for that operation.

I'm a dentist, and I prefer to use a ceramic electronic oven which is more accurate and it's available in any good Dental Lab.

You can read my trouble by visiting the following link:

http://forums.steves-digicams.com/forums/view_topic.php?id=587881&forum_id=20&jump_to=866089#p866089

Please help me regarding this issue.

Soubhi Sabbagh
email: lego(at)aloola.sy
GSM [phone]

[bluntknife]

Sorry I'm very new to this and have a newbie question. Once you have 'dabbed' the solder paste onto the components legs where do you apply the flux? Do you smear it all over the pcb area where the surface mount component will be connected or do you have to precisely apply the flux to each of the legs too? Thanks.

[robomaniac]

He is building a Quatrocopter!

[royalestel]

Cool! Er, Hot! Thanks!!!

[ahb]

Great instructable, and I am going to do it soon. I do have one question though, how would a two-sided PCB done?

[jbeale]

I don't know how you could do 2-sided reflow PCBs yourself. The board houses do this by using two different temperature solders. They do one side with a high-temp solder and after that's cooled, load and reflow the other side at a lower temperature so the first side never reaches the melting point again. Alternatively, it may be they can do IR heating that is fast enough to not melt the bottom side.

[MJM]

Two sided reflow is usually performed with the same solder alloy. The board is flipped over after the first soldering step and new components are placed on top of the board and another soldering process is performed at similar temp. The surface tension of the molten solder will hold most devices in place. Obviously, very large components will fall off - so an adhesive is used to hold those parts on.

[Boss_Sauce]

curious why you're not using the temp. probe from the timer? also, that plastic box and timer should get really hot on top of the oven.